Removable liner and inflatable bladder for snowboard boots and method of manufacture

Abstract

An inflatable liner for a boot, such as a snowboard boot. An oily chalk like substance consisting of 90% sweet starch, 9% lubricant, and 1% stearate is included between two sheets of plastic that make up bladder of the liner. The bladder is attached to the EVA of the liner before the EVA is folded, stitched, heated and molded. This allows the bladder to be attached while the EVA is still flat and allows attachment to be performed by machine stitching. The bladder is partially iflated before the EVA is heated and molded. The oily chalk like substance and the partial inflation of the bladder allows the installed baldder to apss through the heating and molding steps of the EVA without the two sheets that make up the bladder melting together. The design and installation of the bladder minimizes the amount of slipping of a wearer's foot and heal within the boot.

Description

[0001] This application is a continuation in part of U.S. application Ser. No. 09 / 484,130 filed Jan. 14, 2000, now U.S. Pat. No. 6,189,172.FIELD OF THE INVENTIONS[0002] The inventions described below relate to the field inflatable liners for shoes and boots, and their method of manufacture. More specifically, the invention relates to unique removable snowboard boot liners made from Ethyl Vinyl Acetate (EVA) containing an air bladder and their method of manufacture.BACKGROUND OF THE INVENTIONS[0003] While removable liners present many advantages, one major disadvantage associated with removable liners is that the foot of an athlete wearing a snowboard boot with a removable liner has a tendency to slip and move within the boot. This slipping may be caused by the athlete's foot moving within the liner, by the lliner moving within the boot, or by a combination of these two phenomena. The most common result of this slipping is that the heal of the athlete lifts up from the bed of the boo...

AI Technical Summary

Benefits of technology

[0020] The present method solves this problem by introducing a substance between the two sheets that make up the air bladder prior to the sealing of the seams of the bladder and partially inflating the air bladder prior to the heating and molding of the EVA liner. The introduction of this substance and partial inflation of the bladder keep the two sheets that make up the bladder separated during the heating and molding of the EVA. In addition, the disclosed design and installation of the bladder minimizes the amount of slipping of the athlete's foot within the liner and minimizes the amount of lifting of the athlete's heal from the bed of the boot.

Problems solved by technology

While removable liners present many advantages, one major disadvantage associated with removable liners is that the foot of an athlete wearing a snowboard boot with a removable liner has a tendency to slip and move within the boot.

The most common result of this slipping is that the heal of the athlete lifts up from the bed of the boot.

This slipping and lifting makes it more difficult for the athlete to control the snowboard, results in blisters and increases the likelihood of more serious injuries to the athlete.

This slipping problem has been found in the context of ski boots.

Thus, the overall inflation level of the bladder system is fixed and may not be readily adjusted.

Holstine does not disclose how his boot is to be produced.

Potter, et al. do not disclose how their product is to be produced.

Nishimura does not disclose the methods used to manufacture his products.

Nor does Nishimura disclose the use of EVA as a liner material.

None of the foregoing prior art have suggested snowboard boot liners made of EVA having an inflatable air bladder incorporated therein and the mass production of such liners.

It would be extremely difficult, if not impossible, to attach the air bladder by machine stitching once the EVA has been folded, stitched, heated and molded.

Prior to the invention of the method described in this patent, it was not possible to attach an air bladder made from typical materials known in the art of footwear air bladders prior to the heating and molding of the EVA.

This is because the two sheets that make up the air bladder would melt together when the bladder went through the heating and molding process with the EVA-Thus, the bladder could not be inflated and would be useless.

This made the mass production of EVA snowboard boot liners with inflatable bladders impractical.

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